1. Field of the Invention
This invention relates to insect repellents and more particularly to certain novel carboxamides containing an alicyclic moiety and their use as insect repellents.
2. Description of the Prior Art
There is a continuing need for insect repellents or formulations thereof that are significantly more effective or longer lasting than those now in use. All of the repellents now in use for application to the skin have disadvantages, that is, they are not effective for long enough periods of time and are subject to loss by abrasion, evaporation, absorption, and immersion in water. Moreover, all cause a stinging sensation when they contact the eyelids and lips, and are effective only when they are present on the skin or clothing in relatively large quantities. Mosquitoes, sand flies, black flies, stable flies, tsetse flies, gnats, and tabanids are among the many species of biting fly that cause annoyance and distress throughout the world. Many species of biting insects spread human and animal diseases. There are many areas throughout the world in both developed and developing nations where the use of protective clothing and repellents is the only means available to individuals for personal protection. Deet (N,N-diethyl-m-toluamide) has proved to be the most outstanding all-purpose individual repellent yet developed (Proceedings of a Symposium, University of Alberta, Edmonton, Canada, May 16-18, 1972, Defense Research Board, Ottawa, Canada, 1973. DR-217: 109-113). Deet was reported as a promising repellent in 1954 (Journal of Organic Chemistry, 19, 493, 1954). Since that time, no repellent has been reported as being superior to deet as an all-purpose repellent despite a continuing search for such a chemical.